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A porphyritic igneous rock is one with a texture containing large isolated crystals (phenocrysts) in a mass of fine grained crystals . Porphyritic texture indicates that a magma has gone through a two stage cooling process. The magma has cooled sufficiently underground to allow some minerals to crystallize and grow in size; the magma is then expelled above ground where the remaining liquid magma solidifies quickly, allowing only small crystals to develop.

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What igneous rocks are both intrusive and extrusive?

The igneous rocks that can be both intrusive and extrusive are known as porphyritic rocks. These rocks form when magma partially cools underground (intrusive) before being erupted onto the Earth's surface where the remaining magma cools quickly (extrusive). This dual cooling process creates distinctive textures in the rock, with larger crystals (phenocrysts) embedded in a finer-grained matrix.


Is basalt an intrusive rock or extrusive rock?

Extrusive. Solidifies above ground level.


Which igneous rock can be intrusive and extrusive?

A porphyritic igneous rock demonstrates some extrusive characteristics and some intrusive characteristics. The appearance of phenocrysts (larger crystals) in a fine matrix (small crystals) indicates that the magma had time to cool slowly enough underground to form larger crystals before being erupted at or near the surface.


Is schist an intrusive or extrusive rock?

Neither, Igneous rock is either intrusive or extrusive. Thats what intrusive and extrusive is... A igneous rock.


Is a metamorphic rock intrusive or extrusive?

It is neither. Intrusive and extrusive are terms used to describe igneous rock.


Is Obsidian an extrusive rock or intrusive rock?

Yes it is extrusive love yall


Are basalt extrusive or intrusive?

Basaltic rock are true to be extrusive rock


Igneous rocks with a two-stage intrusive-extrusive origin are recognized by a texture which is?

Recognized by a porphyritic texture, where large crystals (phenocrysts) are embedded in a fine-grained matrix. This indicates that the rock underwent two stages of cooling, with the phenocrysts forming during the slow cooling in the intrusive stage, followed by rapid cooling during the extrusive stage to form the fine-grained matrix.


Is extrusive a rock?

Igneous rocks can be categorized as either extrusive or intrusive.


What are the types of Igneous rock?

extrusive and intrusive


What are the type of igneous rock?

extrusive and intrusive


Is dacite intrusive or extrusive?

Dacite can be both intrusive and extrusive. Intrusive dacite forms when magma solidifies beneath the Earth's surface, while extrusive dacite forms when lava erupts on the Earth's surface and cools quickly.